scholarly journals Multivariate spatial feature selection in fMRI

Author(s):  
E Jolly ◽  
L J Chang

Abstract Multivariate neuroimaging analyses constitute a powerful class of techniques to identify psychological representations. However, not all psychological processes are represented at the same spatial scale throughout the brain. This heterogeneity is apparent when comparing hierarchically organized local representations of perceptual processes to flexible transmodal representations of more abstract cognitive processes such as social and affective operations. An open question is how the spatial scale of analytic approaches interacts with the spatial scale of the representations under investigation. In this article, we describe how multivariate analyses can be viewed as existing on a spatial spectrum, anchored by searchlights used to identify locally distributed patterns of information on one end, whole brain approach used to identify diffuse neural representations at the other and region-based approaches in between. We describe how these distinctions are an important and often overlooked analytic consideration and provide heuristics to compare these different techniques to choose based on the analyst’s inferential goals.

2018 ◽  
Author(s):  
Kevin J. Miller ◽  
Matthew M. Botvinick ◽  
Carlos D. Brody

AbstractHumans and animals make predictions about the rewards they expect to receive in different situations. In formal models of behavior, these predictions are known as value representations, and they play two very different roles. Firstly, they drive choice: the expected values of available options are compared to one another, and the best option is selected. Secondly, they support learning: expected values are compared to rewards actually received, and future expectations are updated accordingly. Whether these different functions are mediated by different neural representations remains an open question. Here we employ a recently-developed multi-step task for rats that computationally separates learning from choosing. We investigate the role of value representations in the rodent orbitofrontal cortex, a key structure for value-based cognition. Electrophysiological recordings and optogenetic perturbations indicate that these representations do not directly drive choice. Instead, they signal expected reward information to a learning process elsewhere in the brain that updates choice mechanisms.


Author(s):  
David J. Nutt ◽  
Liam J. Nestor

The brain is involved in controlling necessary motivational and cognitive processes optimized for survival. These processes can be disrupted by substances of addiction. The key neural substrates underlying these processes are made up of a network of four independent and overlapping brain circuits. These circuits govern reward processing, motivation and/or drive, learning and memory, and cognitive control. Anomalies within these circuits may also pre-date the addiction state, and facilitate the progress from experimentation to substance addiction. The subsequent excessive and chronic use of substances further exacerbates these abnormalities. Therefore, these brain circuits and key psychological processes related to their functioning must be understood if we are to develop and test new pharmacological and psychological treatment approaches in substance addiction.


2021 ◽  
Author(s):  
Hugh McGovern ◽  
Marte Otten

Bayesian processing has become a popular framework by which to understand cognitive processes. However, relatively little has been done to understand how Bayesian processing in the brain can be applied to understanding intergroup cognition. We assess how categorization and evaluation processes unfold based on priors about the ethnic outgroup being perceived. We then consider how the precision of prior knowledge about groups differentially influence perception depending on how the information about that group was learned affects the way in which it is recalled. Finally, we evaluate the mechanisms of how humans learn information about other ethnic groups and assess how the method of learning influences future intergroup perception. We suggest that a predictive processing framework for assessing prejudice could help accounting for seemingly disparate findings on intergroup bias from social neuroscience, social psychology, and evolutionary psychology. Such an integration has important implications for future research on prejudice at the interpersonal, intergroup, and societal levels.


2019 ◽  
Author(s):  
Deniz Ertekin ◽  
Leonie Kirszenblat ◽  
Richard Faville ◽  
Bruno van Swinderen

AbstractSleep is vital for survival. Yet, under environmentally challenging conditions such as starvation, animals suppress their need for sleep. Interestingly, starvation-induced sleep loss does not evoke a subsequent sleep rebound. Little is known about how starvation-induced sleep deprivation differs from other types of sleep loss, or why some sleep functions become dispensable during starvation. Here we demonstrate that downregulation of unpaired-2 (upd2, the Drosophila ortholog of leptin), is sufficient to mimic a starved-like state in flies. We use this ‘genetically starved’ state to investigate the consequences of a starvation signal on visual attention and sleep in otherwise well-fed flies, thereby sidestepping the negative side-effects of undernourishment. We find that knockdown of upd2 in the fat body is sufficient to suppress sleep while also increasing selective visual attention and promoting night-time feeding. Further, we show that this peripheral signal is integrated in the fly brain via insulin-expressing cells. Together, these findings identify a role for peripheral tissue-to-brain interactions in the simultaneous regulation of sleep and attention, to potentially promote adaptive behaviors necessary for survival in hungry animals.Author SummarySleep is important for maintaining both physiological (e.g., metabolic, immunological, and developmental) and cognitive processes, such as selective attention. Under nutritionally impoverished conditions, animals suppress sleep and increase foraging to locate food. Yet it is currently unknown how an animal is able to maintain well-tuned cognitive processes, despite being sleep deprived. Here we investigate this question by studying flies that have been genetically engineered to lack a satiety signal, and find that signaling from fat bodies in the periphery to insulin-expressing cells in the brain simultaneously regulates sleep need and attention-like processes.


2020 ◽  
Author(s):  
Yaelan Jung ◽  
Dirk B. Walther

AbstractNatural scenes deliver rich sensory information about the world. Decades of research has shown that the scene-selective network in the visual cortex represents various aspects of scenes. It is, however, unknown how such complex scene information is processed beyond the visual cortex, such as in the prefrontal cortex. It is also unknown how task context impacts the process of scene perception, modulating which scene content is represented in the brain. In this study, we investigate these questions using scene images from four natural scene categories, which also depict two types of global scene properties, temperature (warm or cold), and sound-level (noisy or quiet). A group of healthy human subjects from both sexes participated in the present study using fMRI. In the study, participants viewed scene images under two different task conditions; temperature judgment and sound-level judgment. We analyzed how different scene attributes (scene categories, temperature, and sound-level information) are represented across the brain under these task conditions. Our findings show that global scene properties are only represented in the brain, especially in the prefrontal cortex, when they are task-relevant. However, scene categories are represented in the brain, in both the parahippocampal place area and the prefrontal cortex, regardless of task context. These findings suggest that the prefrontal cortex selectively represents scene content according to task demands, but this task selectivity depends on the types of scene content; task modulates neural representations of global scene properties but not of scene categories.


2015 ◽  
Vol 38 ◽  
Author(s):  
Julian Kiverstein ◽  
Mark Miller

AbstractPessoa (2013) makes a compelling case for conceiving of emotion and cognition as deeply integrated processes in the brain. We will begin our commentary by asking what implications this view of the brain has for an ontology of cognition – a theory of what cognition is and what cognitive processes exist. We will suggest that Pessoa's book, The Cognitive-Emotional Brain, provides strong support for an embodied theory of cognition. We end our commentary by offering some speculation about how Pessoa's arguments naturally extend to social cognition.


2008 ◽  
Vol 28 ◽  
pp. 191-204 ◽  
Author(s):  
Ching-fen Hsu ◽  
Annette Karmiloff-Smith

Most aspects of human life—from gene expression, to brain structure/function, to underlying linguistic and cognitive processes, through to overt language production and comprehension behaviors—are the result of dynamic developmental processes, in which timing plays a crucial role. So, the study of language acquisition in developmental disorders such as Williams syndrome (WS) needs to change from the still widely held view that developmental disorders can be accounted for in terms of spared versus impaired modules to one that takes serious account of the fact that the infant cortex passes from an initial state of high regional interconnectivity to a subsequent state of progressively increasing specialization and localization of functional brain networks. With such early interconnectivity in mind, developmental neuroscientists must explore the possibility that a small perturbation in low-level processes in one part of the brain very early in development can result in serious deficits in higher-level processes in another part of the brain later in development. Therefore, in profiling developmental disorders of language such as in WS, it is vital to start in early infancy, from which to trace the full trajectory of the interactions of language and other cognitive processes across infancy, toddlerhood, and childhood, through to adolescence and adulthood.


2021 ◽  
pp. 1-17
Author(s):  
Avital Sternin ◽  
Lucy M. McGarry ◽  
Adrian M. Owen ◽  
Jessica A. Grahn

Abstract We investigated how familiarity alters music and language processing in the brain. We used fMRI to measure brain responses before and after participants were familiarized with novel music and language stimuli. To manipulate the presence of language and music in the stimuli, there were four conditions: (1) whole music (music and words together), (2) instrumental music (no words), (3) a capella music (sung words, no instruments), and (4) spoken words. To manipulate participants' familiarity with the stimuli, we used novel stimuli and a familiarization paradigm designed to mimic “natural” exposure, while controlling for autobiographical memory confounds. Participants completed two fMRI scans that were separated by a stimulus training period. Behaviorally, participants learned the stimuli over the training period. However, there were no significant neural differences between the familiar and unfamiliar stimuli in either univariate or multivariate analyses. There were differences in neural activity in frontal and temporal regions based on the presence of language in the stimuli, and these differences replicated across the two scanning sessions. These results indicate that the way we engage with music is important for creating a memory of that music, and these aspects, over and above familiarity on its own, may be responsible for the robust nature of musical memory in the presence of neurodegenerative disorders such as Alzheimer's disease.


Author(s):  
Jerome Kagan

This chapter discusses contextual constraints on brain profiles. The laboratories that measure brain activity contain uncommon combinations of physical features and incentives that prime some brain sites and suppress others. Despite these possibilities, neuroscientists continue to speculate about the implications of the brain patterns they record as if the context has a minimal influence on their observations. This position is difficult to defend given the fact that the parahippocampal cortex binds objects and events to the context in which they appear. Adults lying supine and still in the narrow tube of a magnetic scanner in an unfamiliar room are in an unusual psychological and bodily state. The compromised sense of agency, awareness of being evaluated, confinement in a narrow space, and the demand to suppress all movement affect brain and psychological processes.


Author(s):  
Giuseppe Curcio ◽  
Sara Peracchia

In the last years, it is ever more frequent to read popular press stories about the effects of video and/or computer games on the brain and on the behavior. In some cases, we can read something claiming that video games “damage the brain,” while in others these activities can “boost brain power,” and such conflicting proclamation create confusion about the real or potential effects of this activity on human beings. Thus, it is very interesting to deeply understand the effect that exposure to video games (VGs) can have on cognitive processes, with particular attention to decision making. Only a few studies have been carried out on this issue: the main aim of this contribution is to clarify these aspects, critically reviewing the existing scientific literature. Particular attention has been dedicated to normal and pathological players, different types of VGs, and moral aspects of decision making vulnerable to VGs. It has been concluded that research in this area is still in its early days, and this short review aims at discussing several issues and challenges that should be addressed to forward this research field.


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